A True Story (from The Latest Edition Of Australian Aviation Magazine)

A true story (from the latest edition of Australian Aviation magazine):

After a particularly lousy landing by the co-pilot of an
Australian commercial airline, that co-pilot heard the Captain announce
"Ladies and Gentlemen, XXX airlines wishes to apologise for that
rough landing provided today by our first officer".

Some months later the same crew were together and, you guessed it,
the Captain did an even worse one.
The First Officer immediately jumped on the intercom announcing
"Ladies and Gentlemen, XXX airlines wishes to apologise for that
rough landing provided today by our Captain".

The Captain immediately responded angrily, "What did you say
that for?".
The First Officer replied "Remember a couple of months back?
I owed it to you!".